Inside form for sewer-work.



No. 783,575. PATENTED FEB. 28, 1905. G. GUSTAFSON.

INSIDE FORM FOR SEWER WORK.

APPLIOATION FILED JULY 6. 1904.

N0. 783,575. PATENTED FEB. 28, 1905. O.v GU STAPSON.

INSIDE FORM FOR SEWER WORK.

SSSSSSSSSSSSS 2.

M. L "Wm Itifo. 1783,1575.

lUnrrnh @mamns Patented February 28, 1905.

farnuithudcn.

Oltlfltill GUSTAFSON, OF OAKLAND, OALlFORN] A, ASSlhNOlt TO it. B. 8: A.L. STONE COMPANY, OF OAKLAND, (lALlliORNlA, A OOHPORATlON OF ,lllllttllliil li-F. FOFiWl FUN SEWIlEft-"WOWM.

SPECIFICATION forming part of Letters Patent No. 783,575, dated February28, 1905.

Application filed July 6, 1904. Serial No. 215,487.

To a, when] it 111/114 concern:

Be it known that .l', t/nns'r Gus'riirson', a ci tizcn of the UnitedStates, residing at Oakland, county of Alameda, State of California,have invented certain new and useful lmpro vemeuts in l nside Forms forSewerork; and I do hereby declare the following to be a full, clear, andexact description of the same.

The present invention relates to an improved t inside form for use inconnection with the construction of concrete or brick sewers, culverts,or similar structures, the same comprising a series of form-sectionsdetachably connected with means for expanding and con- 5 tracting thesaid sections in order to increase and decrease the size of the formcircumferentially, the object of the invention being to enable the formto be readily adjusted to the inside circumference of the sewer orculvert to be constructed and quickly released after the formation ofone section of the work in order that the form may be easily advancedand placed in position for the construction of an additional section ofthe work.

To ctmrprehend the invention, reference should be had to theaccompanying sheets of drawings, wherein Figure 1 is an end view of acompletei l sec tion of a cylindrical sewer with the form illus- 3trated in adjusted position, the bottom sections of the form beingbroken away for the pru'pose of illustrating one style of means forexpanding and contracting the form circumferentially. Fig. 2 is a planview of the bot tom sections of the form, which illustrate the style ofadj usting means preferably employed where the form is a1iproximately acomplete circle. Fig. 2) is a detail perspective view, partly broken,disclosing; a completed section 4 of sewer within its trench, the formpositioned for an advance section of the work, said form being partlybroken away and a section of the completed lloor of the sewer advancedbeyond the form, the completed floor of the sewer being sectioned online a: :c, Fig. 4:, of the drawings; and Fig. l is an end View of theparts set forth in Fig. 3 of the drawings.

The nui'neral l is used to designate a conipleted section of an ordinaryconcrete sewer,

and 2 the floor thereof, that portion of the 5 sewer above the limits 3of the floor being constructed over the inside form t, which serves as asupporting inner shell for the material of which the sewer orcylindrical tube is constructed. This form in the present case cousistsof live distinct sections, of which 5 constitutes the floor-sections,(3the bench-sections, and T the crmvn-section. -Ilowe\ 'er, it must not belunlerstood that a limitation given as to the number of form-sectkmsthat are employed, for such is an immaterial feature of the invention,inasmuch as the said number of sections imiy be increased or decreasedat will.

Preferably each form-section consists of four united ribs 8, so spacedas to produce a section of approximately eight feet in length. The outerface of each rib is curved to conform to the arc of the smver-sectionwhich it is supposed to act as a support for. The ribs of theform-sections, at least those for the bench and crown sections, areprovided with an outer face-covering E), which in the present caseconsists of a series of parallel wooden strips.

The sections 5 and (3 and 7 are detachably connected by means of thelock-studs 10, which studs engage with the almtting plates or shouldersl l, secured, respectively, to the upperand lower edge of each end ribof sections 6 and 7 and the upper edge of the ribs of section Thedescribed locking means are of an exceedingly simple character, and forsuch reason the same are employed, although any other suitable devicesfor locking the said sec 5 tions may be utilized.

The lower or lioor sections 5 are preferably skeleton sections,consisting of the curved ribs 8 and the longitudinal rods or plates 1212. The lower rod or plate 12 of said opposing sections 5 are adjustablyconnected by means of the screw-bolts 13, which bolts as screwed inwardand outward move the said sections toward and from each other. thesesections are adjusted the entire inside form is contracted or expanded,as the case maybe.

It is not required that the floor-sections be provided with an outerfame-covering, in-

asmuch as the floor of the concrete-work may be properly shaped withoutthe use of a form.

After the construction of the floor of the sewer the form is required toenable the formation of the remainder of the sewer-wall. The respectiveform-sections are united or locked together by the lock means and thefloor-sections then adjusted toward and from each other by the adjustingmeans until the circumference of the form is that required for theinside wall of the sewer, which form is left in place until thecompletion and settingof the sewer-section thereover. While one sectionof the sewer is setting or hardening, another form is put in place forthe formation of an advanced section of the work. The first form withinthe completed section of the sewer-work is then removed to a position inadvance of the second formed section of the work in order that thesecond advance section of the work may be constructed.

To remove any given form, it is only required to slightly contract theform by adjusting the floor-sections toward each other, when theremaining sections of the form may be readily disconnected or detached.hen thus released, each section is passed through the set form of theadvance-section of the work for placing together for the formation of anew section of the Work.

The essential feature of the present invention resides in the employmentof a series of detachably connected form sections, with means forexpanding and contracting the united sections circumferentially, wherebythe form may be quickly and easily adjusted to the required size of thesewer-work and readily taken apart for the purpose of removal. Thesefeatures it is desired to claim,

broadly, whatever form of adjusting means may be employed forcontracting and expand ing the form-sections circumferentially orwhatever style of interlocking means be utilized for connecting thesections.

Having thus described the invention, what is claimed as new, and desiredto be protected by Letters Patent, is

1. An inside form for sewer-work of the character described comprising aseries of form-sections detachably connected one to the other and meansinterposed between the adjacent ends of twoiof said sections forcontracting and expanding the connected sections cireumferentially.

2. An inside form for sewer-work of the character described comprising aseries of form-sections detachably connected one to the other and athreaded connection interposed between the adjacent ends of two of saidsections, said bolt being in threaded engagement with one of saidsections, whereby said connected sections may be contracted or expandedcircumferentially.

3. An inside form for sewer-work of the character described comprising aseries of form-sections, each of said sections being provided at itsends with projecting plates which abut against the corresponding platesof the adjacent sections when the sections are assembled,lock-studsdetachably connecting the abutting plates of the adjacent sections, andmeans interposed between the adjacent ends of two of said sections forexpanding and contracting the connected sections circumferentially.

In witness whereof I have hereunto set my hand.

CREST GUSTAFSON.

\Vitnesses:

N. A. ACKER, D. B. RICHARDS.

